Process for producing resins of petroleum origin



Nov. 20, 1934; v I FULTON I 1,981,824

PROCESS OF PRODUCING RESINS OF PETROLEUM ORIGIN Filed Oct. 30 1.931

Patented Nov. 20, 1934 UNITED" STATES PROCESS FOR PRODUCING RESINS OFPETROLEUM ORIGIN 1 Stewart 0. Fulton, Elizabeth, N. J assignor toStandard Oil Development Company, a corporation of Delaware ApplicationOctober 30, 1931, Serial No.

4 Claims.

This invention relates to the productionof synthetic resins from crackedtaroils of petroleum origin and certain other petroleum distillates bycondensation by means of chlorination 5 and will be understood from thefollowing descriptionwhenreadin conjunction with the drawing, which is asemi-diagrammatic side elevation,

partly in section, of a suitable apparatus.

Cracked tar of petroleum origin obtained in liquid or vapor phasecracking, or any similar process involving cracking, is used as thepreferred raw material for the production of resins. The tar which mayhave a gravity of, say, -11 A. P. I., is first subjected todistillation, preferably under vacuum, to remove the oily componentsoverhead. If a high vacuum, for example, 1 mm. mercury, is used, theoily compo-, nents will distill over between the approximatetemperatures of 300 F. to 660 F. corresponding I to about 600 F., andabout 1100 F. respectively at atmospheric pressure. However, it is notnecessary to use such an extreme vacuum, but less vacuum with or withoutsteam or other distillation aid may also be used and the'distillationmay even be carried out under atmospheric pressure using steam or othergaseous agent as carrier. Usually about 85% of the tar is obtained asdistillate.

r The distillate is then chlorinated preferably 'by bubbling chlorinethrough it slowly. The temperature at which the chlorination is carriedout may be ordinary'room temperature or it may be somewhat higher, sayup to 150 F., depending on the viscosity of the distillate. The productto be chlorinated is preferably agitated while the chlorine is bubbledthrough it. The chlorination is continued until 10 to of chlorine isabsorbed, although it may be interrupted earlier or may be carried outfurther, depending on the scrbed may be determined by any of the knownanalytical methods, or it may be roughly estimated by the increase ofweight of the product. The chlorinated product is then heated in a stillup to a temperature of about 660 F., first underatmosphericpressure,then under vacuum, the final step in the heating being preferablycarried out under 1 mm. mercury pressure and at a temperature up to 660F. The heating simultaneously removes as overhead products the chlorinein the form of hydrochloric acid and the oily products. Only traces ofchlorine are found in the hydrocarbon material carried overhead and inthe residue.

Thebottoms remaining in the still is cooled product desired. The amountof chlorine ab-- down to about 200 F. and then agitated with about threetimes its weight of a selective solvent for resin such as lightpetroleum hydrocarbon distillate (naphtha). to extract the resinousprod- Although the solvent described is preferred, it

will be understood that the present invention is I in no way limitedthereto.

Instead of using agitation the still bottoms may be refluxed with thehydrocarbon solvent. In either case the solution is separated from thehydrocarbon insoluble material, the amount of which varies from 0% to50% of the weight of the bottoms. The separation is effected by settlingand decantation or by filtration, or by other methods of separationknown in the art. The hydrocarbon solvent is then removed from thedissolved resin by distilling the solution under atmospheric pressure onunder slight vacuum, leaving as distillation residue the final resinproduct. When a light-colored resin is required the solution in Varsolor naphtha is acid-treated before the final distillation step.

The concentration of the sulfuric acid used for this purpose is 95% moreor less. The amount of the acid will be regulated according tot-hedesired color of the final resin, and may vary within wide limits, sayfrom 10% to 50% of the resinous material dissolved in the solvent. Theacid sludge is separated and the solution is neutralized, either bycontacting with fine clay or by washing with water or dilute alkali. Theacid treated and neutralized solution is distilled to remove the naphthafrom the resin, if a solid resin is required.

The yield of resin is on the average 15% of the tar distillate and willdepend upon the degree.

of "chlorination. The more thorough the chlorination, the higher will bethe softening point of the resin. The latter is' above about 80 F. andusually between and 225 F. ascletermined by the ball and ring method..Increased chlorination, however, also increases the hydro carboninsoluble material and consequentlydecreases the yield. The finalcondensed resin is an unsaponifiable solid, odorless and tasteless, and

has a yellow to reddish-brown color. The color is lighter when acidtreating is employed. In 5 the latter case the resin is transparent inthin plates of say centimeter thickness. It is soluble in petroleumnaphtha, linseed oil, China wood oil, esters and benzol, and insolublein water, lower alcohols and acetone.

The tar is often advantageously distilled in two steps. The first 60% isdiscarded and used as heating oil, and only the last 40% is used asstarting material for the production of resins. Instead of the tardistillate other equally high boiling petroleum oils such as for examplethe sulfur dioxide extract of a petroleum distillate which is rich inaromatic and/or unsaturated hydrocarbons may be used for producingresins, if it has a distillation range within approximately 300 F. to660 F. under an absolute pressure of 1 mm. mercury. Other hydrocarbonssuch as distillates from an asphalt base crude, etc., may also be usedas raw materials if they fall within the same approximate distillationrange.

My process may be varied in different ways without departing from thespirit of the invention. Thus, for example, light colored resin may beprepared without using an acid treat. For this purpose the bottomsremaining in the dechlorinating still are dissolved in a small quantityof solvent such as ethylene dichloride, benzol,

etc. A light parafiinic hydrocarbon such as petroleum ether, liquefiedpentane or butane is then added to the solvent whereby the materialdissolved, other than the resin, is precipitated and a fairly pure resinsolution is obtained which does not need acid treatment. In anothermodification, still bottoms may be directly extracted by heating atatmospheric or higher pressure with a light parafiinic hydrocarbon suchas petroleum ether, butane or pentane. In this'case aga'n the resin goesinto solution without appreciable amounts of contaminants. The resinsolutions may be used either as such or the solvent may be evaporated ifa solid resin is required. The

products obtained by my process may be characterized according to theirsource as resinified cracked tar oil or more generally as a resinifiedhydrocarbon distillate of petroleum origin.

Referring now to the drawing, 1 is a chlorinating vessel, 2 and 3 arethe lines for introducing the distillate and the chlorine respectively,4 the line for removing the evolved gases of chlorine, and hydrochloricacid, 5 a scrubber to re- 55. .move the hydrochloric acid, and 6 areturn line for the'chlorine, '7 is the still for dechlorinating theproduct with an overhead line 8 and a bottoms line and cooler 19 and thebottoms draw-off line 18 thru which the resin obtained as a residue isdrawn off, cooled and sent to storage tank, (not shown).

The following example will serve to illustrate my process:

1,000 pounds of tar distillate from a cracking coil tar (10 A. P. 1.)representing the total overhead boiling up to 660 F. at 1 mm. pressure,was chlorinated until the percentage of combined chlorine reached 9.7%.The chlorinated distillate was then heated up to 660 F. in the still 7provided with a condenser at atmospheric pressure, whereupon most of thechlorine was removed as hydrochloric acid. Then the distillate wassubjected to a vacuum distillation under reduced pressure until atemperature corresponding to 660 F. at 1 mm. pressure was reached. 208pounds of high softening point residue (S. P. 282 F. ball and ringmethod) was obtained in this way, which was extracted with light naphthaleaving an insoluble residue amounting to pounds. After removal of thenaphtha by distillation 133 pounds of light colored resin was obtainedhaving a softening point of 183 F. (ball and ring method). I

This invention is not to be limited by any theory or the particulardetails given for purpose of i1- lustration, but only by the followingclaims in which it is my intention to claim all novelty inherent in theprocess.

I claim:

1. A solid hydrocarbon resin produced by chlorination and dechlorinationof a distillate boiling above about 300 F. at 1 mm. mercury absolutepressure, from a cracked petroleum tar, said resin being anunsaponifiable solid, clear, light yellow to reddish brown color,softening point above F., soluble in petroleum naphtha, linseed oil andbenzol and insoluble in water, lower alcohols and acetone.

2. Process for producing a resin, which comprises chlorinating adistillate, boiling within the approximate limits of 300 to 660 F. underan absolute pressure of 1 mm. mercury, from a cracked petroleum tar,heating the chlorinated distillate under a pressure below atmospheric toremove the chlorine and oily constituents therefrom as distillate,treating the remaining residue, substantially free from oily materials,with a selective solvent for resin, and separating the insolubleproducts from the solution containing the resin. I

3. Process for producing a resin, which comprises chlorinating adistillate, boiling above about 300 F. at 1 mm. mercury absolutepressure, from-a cracked petroleumtar, dechlorinating the chlorinateddistillate by heatingit to about 660 F. under vacuum, and extracting aresin from the dechlorinated residue product with 5 a solvent.

4. Process according to claim 3; in which the hydrocarbon distillatetreated boils within the approximate limits of 300 to 660 F. under anabsolute pressure of 1 mm. mercury.

STEWART C. FULTON.

